This great info appears in the FAQ section concerning setting base idle specs for LH 2.1, 2.2: (kinda hard to find though under- Engine: Fuel injection/Throttle body and Throttle position switch adjustment)


Go to the right inner fender well (740’s) or the left inner fender well (240’s) and find the red and white pigtail that sits besides the ignition ECU. This is your CIS test point. Ground this connector and adjust the bypass air thumbscrew on the throttle body until the idle is 725 RPM’s. Remove the ground from your test point; the idle should be close to 750 RPM’s.
Next to the red and white wire is a green and white pigtail. This is your CO test point. Using Volvo special tool part #9995280 (approx. $35) plug one end of the test LED to the fender well connector and the red connector to the positive terminal of the battery. A logic probe can be used in place of the Volvo special tool or if you are handy build the circuit below. Remove the tamper proof plug from the air mass meter by drilling two 1/8” holes in the plug about 3/16” deep and removing the plug with needle nose pliers or snap ring pliers. This will reveal the CO adjusting screw. Adjust the AMM until the LED on the tester blinks on and off at equal intervals.

By the right fender well does he mean inside the car at FI brain, ECU?
What does CIS mean?????
It would be way worth it to me to spend the $35 bucks to be able to do this
considering a mechanic would charge you $70 an hour.

Thanks

It's pretty easy once you figure out what the FAQ says. I had removed my hood light a while back and the wire feeding it always has 12 volts on it so I just used that wire for the 12 volt LED connection. You can make the led setup very easily. In fact, you can use a 1k ohm resistor. I did not have any 750 ohms laying around the house so I used a 1k and my LED is still very bright. It will stay on all the time if you leave it plugged in with the engine off though. I had to turn my AMM screw about 2 full turns to get the adjustment correct. I would make sure the AMM connectors are clean before doing the adjustment. If you wiggle the AMM connector while the engine is idling and it affects the engine RPM, you have an oxidation problem on the pins (or possible wiring problems). It is very hard to see the oxidation, just clean them very well.

The metal is pretty easy to drill in the plug, but the plug is pretty tight. I ended up replacing my IAC valve because the engine RPM would get stuck. Make sure you talk care of any vaccuum leaks first too or the idle speed adjustment would be a waste of time.

Randy

Thanks, you guys sure know your stuff. Thanks for the tip on the tool. I have built plenty of simple circuits. That tool price should come in now at around a Buck instead of $35. Now we're talkin'!!!!

On my 87 745T w/LH 2.2, this connector is under the hood on the right (passenger) side just forward of the coolant reservoir. It is a dual connector, containing two female spade connectors with one connected to a green and white wire for checking idle mixure and the other connected to a red and white wire for setting idle speed.

Connecting the red and white terminal to ground will close the idle air controller (IAC) allowing you to set the idle speed to 725 RPM with the black plastic knob on the throttle body. The IAC is part of the Constant Idle Speed (CIS) system.

To set mixture, you need to obtain the special tool which you can make out of an LED and a 750 Ohm resistor and some wire. (You can also use a dwell meter.) To set idle mixture, you connect the tool to the green and white wire and the battery + terminal and adjust the mixture screw on the AMM until the LED is on 50% of the time and off 50% of the time. This tool can also be used to troubleshoot the EZK117 ignition system via another connector on the opposite side of the car.

Go to http://www.mvpvolvo.com/ and look for their "setting base idle" document to see the original source of this information, as well as a diagram for making the tool.

HTH
bagle

In your case CIS stands for Constant Idle System, which is a bypass valve that controls the engine idle on volvo cars, the valve is hooked up to the computer (sometimes) and adjusts acording to temprature aircon etc, you can dissable it using the CIS test point so you can reset the base idle back to factory spec.
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Veronica, my 85 760Ti